Composite spinal facet implant with textured surfaces

ABSTRACT

Implementations described and claimed herein provide a distal leading portion of a composite spinal implant for implantation in a spinal facet joint. In one implementation, the distal leading portion includes a distal leading end, a proximal trailing end, a first face, and a second face. The distal leading end has a distal surface generally opposite a proximal surface of the proximal trailing end. The first face has a first surface that is generally parallel with a second surface of the second face. The first and second faces extend between the distal leading end and the proximal trailing end, such that the first and second surfaces slope upwardly from the distal lead end to the proximal trailing end along a length of extending proximally. The first and second surfaces having one or more textured features adapted to provide friction with the spinal facet joint.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority under 35 U.S.C. §119 to U.S. provisional patent application 61/705,375, which was filed Sep. 25, 2012 and entitled “Composite Spinal Facet Implant,” and to U.S. provisional patent application 61/777,643, which was filed Mar. 12, 2013 and entitled “Composite Spinal Facet Implant with Textured Surfaces.”

The present application claims priority to and is a continuation-in-part of U.S. patent application Ser. No. 13/614,372 filed on Sep. 13, 2012, and entitled Vertebral Joint Implants And Delivery Tools. U.S. patent application Ser. No. 13/614,372 is a continuation of U.S. patent application Ser. No. 12/653,283, which was filed on Dec. 10, 2009, now U.S. Pat. No. 8,425,558, and entitled “Verbal Joint Implants and Delivery Tools.” U.S. patent application Ser. No. 12/653,283 claims priority to and is a continuation-in-part of U.S. patent application Ser. No. 12/455,814, which was filed on Jun. 5, 2009, now U.S. Pat. No. 8,361,152 and entitled “Facet Joint Implants and Delivery Tools.” U.S. patent application Ser. No. 12/455,814 claims priority to and is a continuation-in-part of U.S. patent application Ser. No. 12/317,682, which was filed on Dec. 23, 2008, now U.S. Pat. No. 8,267,966, and entitled “Facet Joint Implants and Delivery Tools.”

U.S. patent application Ser. No. 12/455,814 further claims priority under 35 U.S.C. §119 to U.S. provisional patent application 61/169,601, which was filed on Apr. 15, 2009 and entitled “Facet Joint Implants and Delivery Tools.”

U.S. patent application Ser. No. 12/317,682 claims priority under 35 U.S.C. §119 to U.S. provisional patent application 61/109,776, which was filed Oct. 30, 2008 and entitled “Facet Joint Implants,” and U.S. provisional patent application 61/059,723, which was filed on Jun. 6, 2008 and entitled “Spine Distraction Device.”

Each of the aforementioned applications is hereby incorporated by reference in its entirety into the present application.

TECHNICAL FIELD

Aspects of the present disclosure relate to a device for distracting the spine and more particularly to a tool for distracting a facet joint of the spine and an implant for maintaining the distracted position of the joint.

BACKGROUND

Chronic back problems cause pain and disability for a large segment of the population. Adverse spinal conditions may be characteristic of age. In particular, spinal stenosis (including, but not limited to, central, canal, and lateral stenosis) and facet arthropathy may increase with age. Spinal stenosis results in a reduction of foraminal area (i.e. the available space for the passage of nerves and blood vessels), which may compress cervical nerve roots and cause radicular pain. Both neck extension and ipsilateral rotation, in contrast to neck flexion, may further reduce the foraminal area and contribute to pain, nerve root compression, and neural injury.

Cervical disc herniations may be a factor in spinal stenosis and may predominantly present upper extremity radicular symptoms. In this case, treatment may take the form of closed traction. A number of closed traction devices are available that alleviate pain by pulling on the head to increase foraminal height. Cervical disc herniations may also be treated with anterior and posterior surgery. Many of these surgeries are performed through an anterior approach, which requires a spinal fusion. These surgeries may be expensive and beget additional surgeries due to changing the biomechanics of the neck. There is a three percent incidence of re-operation after cervical spine surgery. Moreover, these surgeries may be highly invasive leading to long recovery times.

There is a need in the art for implants, delivery systems, and methods of implantation that facilitate the fusion of a spinal facet joint via a minimally invasive or percutaneous procedure from, for example, a posterior approach.

It is with these observations in mind, among others, that various aspects of the present disclosure were conceived and developed.

SUMMARY

Implementations described and claimed herein address the foregoing problems, among others, by providing a distal leading portion of a composite spinal implant for implantation in a spinal facet joint. In one implementation, the distal leading portion includes a distal leading end, a first face, and a first side. The distal leading end has a distal surface generally opposite a proximal surface of a proximal trailing end. The first face has a first surface that is generally parallel with a second surface of a second face. The first and second faces extend between the distal leading end and the proximal trailing end, such that the first and second surfaces slope upwardly from the distal lead end to the proximal trailing end along a length of extending proximally. The first and second surfaces having one or more textured features adapted to provide friction with the spinal facet joint. The first side has a first side surface generally opposite a second side having a second side surface. The first side surface and the second side surface each have a slot extending distally from a notch formed in the proximal surface until reaching a sloped transition extending from an inner surface of the slot to the side surface of the first side or the second side.

Other implementations are also described and recited herein. Further, while multiple implementations are disclosed, still other implementations of the presently disclosed technology will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative implementations of the presently disclosed technology. As will be realized, the presently disclosed technology is capable of modifications in various aspects, all without departing from the spirit and scope of the presently disclosed technology. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-D are isometric, top plan, distal leading end, and side views, respectively, of an example distal leading portion of a composite spinal implant.

FIG. 2A is an isometric view of another example of a distal leading portion of a composite spinal implant.

FIG. 2B shows an isometric view of an example proximal trailing anchor portion of a composite spinal implant.

FIGS. 2C-2D illustrate side and top plan views, respectively, of a composite spinal implant employing the distal leading portion of FIG. 2A and the proximal trailing anchor portion of FIG. 2B.

FIGS. 3A-C depict isometric, top plan, and proximal trailing end views, respectively, of example composite implants employing different proximal trailing anchor portions.

FIGS. 4A-D show isometric, top plan, distal leading end, and side views, respectively, of an example distal leading portion of a composite spinal implant including textured faces having small pyramids.

FIGS. 5A-D illustrate isometric, top plan, distal leading end, and side views, respectively, of an example distal leading portion of a composite spinal implant including textured faces having large pyramids.

FIGS. 6A-D are isometric, top plan, distal leading end, and side views, respectively, of an example distal leading portion of a composite spinal implant including textured faces having dimples.

FIGS. 7A-D show isometric, top plan, distal leading end, and side views, respectively, of an example distal leading portion of a composite spinal implant including textured faces having grit.

FIGS. 8A-D depict isometric, top plan, distal leading end, and side views, respectively, of an example distal leading portion of a composite spinal implant including textured faces having pits.

FIG. 9 shows an example delivery device and guide tube configured to minimally invasively deliver a composite spinal implant.

FIG. 10 shows a perspective view the delivery device of FIG. 9 and a detailed view of a distal end of the delivery device.

FIG. 11 illustrates a perspective view of the guide tube of FIG. 9.

FIG. 12 depicts a perspective view of an example decorticator.

FIG. 13 shows a perspective view of an example injector.

FIG. 14 is a perspective view of an example chisel.

FIG. 15 illustrates an example place holding chisel.

FIG. 16 depicts a perspective view of an example malleting tool.

DETAILED DESCRIPTION

Aspects of the present disclosure generally involve devices and methods for treating spinal stenosis. Spinal stenosis reflects a narrowing of one or more areas of the spine often in the upper or lower back. This narrowing can put pressure on the spinal cord or on the nerves that branch out from the compressed areas. Individual vertebrae of the spine are positioned relative to each other and their separation is maintained by discs separating main vertebral bodies and by capsules positioned within facet joints. The discs and capsules are separated from the bone of their respective joints by cartilage. Spinal stenosis is often indicative of degeneration of a disc, a capsule, or the cartilage in a joint, which leads to a compression of the joints and the narrowing mentioned.

As such, in one aspect, a device for distracting a facet joint of the spine is provided to remedy this condition. The device may include a tool and an implant for distracting and maintaining the distracted position of the joint. The device may be adapted to access a facet joint by inserting a delivery tool and an implant, forcibly separate the associated articular surfaces with the tool, the implant, or both, and leave the implant in place to maintain the separation of the articular surfaces. This approach may allow for maintaining the distraction of the joint, thereby relieving symptoms associated with spinal stenosis.

In one particular aspect, a composite spinal implant for implantation in a spinal facet joint to bring about the fusion of the spinal facet joint is provided. The composite spinal implant includes a distal leading portion and a proximal trailing anchor portion. The distal leading portion includes at least one face having a textured surface that provides friction between the spinal facet joint and the implant.

For a detailed description of an example distal leading portion 100 of a composite spinal implant, reference is made to FIGS. 1A-D, which are isometric, top plan, distal leading end, and side views, respectively.

The distal leading portion 100 may be formed of a bone or bone substitute material. In one implementation, the distal leading portion 100 includes a distal leading end 102 generally opposite a proximal trailing end 104, a first face 106 generally opposite a second face 108, and a first side 110 generally opposite a second side 112. In one implementation, the first and second sides 110 and 112 each have a length 160 of approximately 10 mm, and the distal leading end 102 and the proximal trailing end 104 each have a length 156 of approximately 5 mm.

The first face 106 extends between the distal leading end 102 and the proximal trailing end 104. In one implementation, the first face 106 is generally parallel with the second face 108. For example, the first face 106 may extend from the distal leading end 102 to the proximal trailing end 104 at an angle of approximately 0° to 15° relative to the second face 108. As such, a height of the proximal trailing end 104 may be greater than or equal to a height of the distal leading end 102. In one implementation, the first and second faces 106 and 108 include textured features 114 that provide friction between the spinal facet joint and the implant.

In the implementation shown in FIGS. 1A-D, the distal leading end 102 includes a distal surface 116 and the proximal trailing end 104 includes a proximal surface 118. In one implementation, the distal and proximal surfaces 116 and 118 are planar surfaces forming a generally rectangular shape. In one implementation, the distal surface 116 has a height 152 that is approximately 0.84 mm, and the proximal surface 118 has a height 154 that is approximately 2.25 mm. The distal surface 116 includes a first pair of distal edges 128 extending between the first and second sides 110 and 112 and a second pair of distal edges 134 extending between the first and second faces 106 and 108. Similarly, the proximal surface 118 includes a first pair of proximal edges 128 and a second pair of proximal edges 120 extending between the first and second faces 106 and 108. In one implementation, where the height of the proximal trailing end 104 is greater than the height of the distal leading end 102, the height of the second pair of proximal edges 120 is greater than the height of the second pair of distal edges 134, such that a surface 124 of the first face 106 and a surface 130 of the second face 108 slope upwardly from the distal leading end 102 to the proximal trailing end 104 along a length 140 extending proximally.

In one implementation, the surface 124 of the first face 106 and the surface 130 of the second face 108 are planar surfaces having a generally rectangular shape formed from the length 140 and a width 126 that is generally coextensive with the first pair of edges 128. The first and second sides 110 and 112 each include a side surface 132 extending between the distal leading end 102 and the proximal trailing end 104. In one implementation, the side surface 132 is a generally planar surface having a pair of opposed edges that are generally coextensive with the second pair of distal edges 134 and the second pair of proximal edges 120.

The surface 124 of the first face 106 and/or the surface 130 of the second face 108 include the textured features 114. In the implementation shown in FIGS. 1A-D, the textured features 114 are one or more ridges extending generally perpendicularly from the surfaces 124 and/or 130 along the length 140. Each of the ridges includes an inner surface 142 generally opposite an outer surface 144. In one implementation, the outer surface 144 of each of the ridges is generally planar and coextensive with the side surface 132, and the inner surface 142 of each of the ridges is a generally planar surface that is generally perpendicular to the surface 124 of the first face 106 and/or the surface 130 of the second face 108. In one implementation, each of the ridges has a saw toothed profile defined by a plurality of teeth having a leading distal face 148, a trailing proximal face 150, and a tip 146 formed at an intersection between the faces 148 and 150. The trailing proximal face 150 has a slope that is different from a slope of the leading distal face 148. For example, the trailing proximal face 150 has a slope that is greater than the slope of the leading distal face 148.

Further, the height of the tips 146 may increase along the length 140, such that teeth positioned near the proximal trailing end 104 have a greater height than teeth positioned near the distal leading end 102. For example, a height 158 extending between the tip 146 of a tooth positioned on the first face 106 and the tip 146 of a tooth positioned on the second face 108 at the distal leading end 102 may be approximately 2.69 mm, and a height 162 extending between the tip 146 of a tooth positioned on the first face 106 and the tip 146 of a tooth positioned on the second face 108 at the distal leading end 102 may be approximately 3.68 mm. The tip 146 may be a truncated flat surface, a point, or other shapes. Further, it will be appreciated that the first and second faces 106 and 108 may include any number or configuration of ridges or teeth and that the textured features 114 may cover all or a portion of the surface 124 of the first face 106 and/or the surface 130 of the second face 108.

In one implementation, the first and second sides 110 and 112 each include a slot 136 defined in the side surface 132 extending distally from a notch 122 formed in the proximal surface 118 at an approximate center of each of the second pair of proximal edges 120. As such, the slot 136 is generally centered in the side surface 132 between the surface 124 of the first face 106 and the surface 130 of the second face 108. In one implementation, the slot 136 is generally dimensionally constant for a majority of a length of the slot 136 extending from the notch 122 until reaching a sloped transition 138 extending from an inner surface of the slot 136 to the side surface 132.

As can be understood from FIG. 2A, in one implementation, the distal leading portion 100 includes at least one of a first groove 164 or a second groove 166 defined in the proximal surface 118 and extending into the surfaces 124 or 130, respectively. The first and second grooves 164 and 166 are adapted to engage a proximal trailing anchor portion 200.

In one implementation, as shown in FIG. 2B, the proximal trailing anchor portion 200 includes a body 202 and one or more anchors 204. The anchor 204 is supported by the body 202 and configured to extend at least one of outwardly from the body 202 or outwardly and distally from the body 202. The proximal trailing anchor portion 200 may be formed of a biocompatible metal, ceramic, polymer, or any combination thereof. In some implementations, the composite spinal implant may be entirely formed of bone or bone substitute material. In this case, the proximal trailing anchor portion 200 may be excluded from the composite spinal implant and the overall length of the distal leading portion 100 extended.

The body 202 includes a distal leading end 206 generally opposite a proximal trailing end 208, a first face 210 generally opposite a second face 212, and a first side 214 generally opposite a second side 216. In one implementation, the first and second faces 210 and 212 include textured features 218. For example, the textured features 218 may include one or more ridges similar to the ridges of the distal leading portion 100 described with respect to FIGS. 1A-D. Other implementations of the proximal trailing anchor portion 200 may include any number or configuration of the textured features 218 covering all or a portion of the faces 210 and 212.

As can be understood from FIGS. 2A-2D, the first and second grooves 164 and 166 in the distal leading portion 100 align with corresponding openings (e.g., an opening 224) in the body 202 of the proximal trailing anchor portion 200 through which the anchor 204 extends so as to allow the anchor 204 to extend through at least a portion of the proximal trailing anchor portion 200 and at least a portion of the distal leading portion 100.

As such, when the proximal trailing anchor portion 200 and the distal leading portion 100 are implanted in the facet joint to form a composite spinal implant, the distal leading end 206 of the body 202 of the proximal trailing anchor portion 200 abuts in a generally planar surface contact with the proximal trailing end 104 of the distal leading portion 100. With the portions 100 and 200 so abutted, slots 220 in the sides 214 and 216 of the body 202 of the proximal trailing anchor portion 200 are generally aligned and dimensionally consistent with the respective slots 136 in the distal leading portion 100, such that a notch 222 in the distal leading end 206 of the proximal trailing anchor portion 200 is aligned with each of the notches 122 of the distal leading portion 100. In one implementation, the slots 220 extend the full length of the body 202 between opposing notches 222 centered along a height of the sides 214 and 216 of the proximal trailing anchor portion 200. Further, when so abutted, each of the side surfaces 132 of the distal leading portion 100 is generally coextensive with a surface of the sides 214 or 216 of the body 202 of the proximal trailing anchor portion 200, and the textured features 114 of the distal leading portion 100 are generally aligned and similarly spaced with respect to the textured features 218 of the proximal trailing anchor portion 200.

As can be understood from FIGS. 3A-C, different proximal trailing anchor portions 200 with a variety of anchors 204 and openings 224 may be utilized. For example, a composite spinal implant 300 includes a pair of generally parallel circular openings 224 extending through the body 202 of the proximal trailing anchor portion 200. A composite spinal implant 302 includes a pair of offset circular openings 224 extending through the body 202 of the proximal trailing anchor portion 200 through which an anchor 204 in the form of a relatively small curved member extends. A composite spinal implant 304 includes a relatively large opening 224 extending through the body 202 of the proximal trailing anchor portion 200 through which an anchor 204 in the form of a screw extends. A composite spinal implant 306 includes a pair of offset circular openings 224 extending through the body 202 of the proximal trailing anchor portion 200 through which an anchor 204 in the form of a relatively large curved member extends. It will be appreciated that the anchor 204 may be one or more of nails, barbed members, threaded members, curved members, screws, and the like. A proximal trailing end of the anchor 204 is actionable at the proximal trailing end 208 of the body 202 so as to cause the anchor 204 to extend from the body 202.

For additional examples of the distal leading portion 100 with various textured features 114, reference is made to FIGS. 4A-8D. It will be appreciated that the proximal trailing anchor portion 200 may be similarly modified to include a variety of textured features 218.

Referring to FIGS. 4A-D, in one implementation, the distal leading portion 100 includes the distal leading end 102 generally opposite the proximal trailing end 104, the first face 106 generally opposite the second face 108, and the first side 110 generally opposite the second side 112. In one implementation, the first and second sides 110 and 112 each have a length 406 of approximately 10 mm, and the distal leading end 102 and the proximal trailing end 104 each have a length 402 of approximately 5 mm.

The first face 106 extends between the distal leading end 102 and the proximal trailing end 104. In one implementation, the first face 106 is generally parallel with the second face 108. A height of the proximal trailing end 104 may be greater than or equal to a height of the distal leading end 102. In one implementation, the first and second faces 106 and 108 include textured features 114 that provide friction between the spinal facet joint and the implant.

In one implementation, the distal leading end 102 includes the distal surface 116 and the proximal trailing end 104 includes the proximal surface 118. In one implementation, the distal and proximal surfaces 116 and 118 are planar surfaces forming a generally rectangular shape. In one implementation, the distal surface 116 has a height 404 that is approximately 2.8 mm. The distal surface 116 includes a first pair of distal edges 128 extending between the first and second sides 110 and 112 and a second pair of distal edges 134 extending between the first and second faces 106 and 108. Similarly, the proximal surface 118 includes a first pair of proximal edges 128 and a second pair of proximal edges 120 extending between the first and second faces 106 and 108. In one implementation, where the height of the proximal trailing end 104 is greater than the height of the distal leading end 102, the height of the second pair of proximal edges 120 is greater than the height of the second pair of distal edges 134, such that a surface 124 of the first face 106 and a surface 130 of the second face 108 slope upwardly from the distal leading end 102 to the proximal trailing end 104 along the length 140 extending proximally.

In one implementation, the surface 124 of the first face 106 and the surface 130 of the second face 108 are planar surfaces having a generally rectangular shape formed from the length 140 and the width 126 that is generally coextensive with the first pair of edges 128. The first and second sides 110 and 112 each include the side surface 132 extending between the distal leading end 102 and the proximal trailing end 104. In one implementation, the side surface 132 is a generally planar surface having a pair of opposed edges that are generally coextensive with the second pair of distal edges 134 and the second pair of proximal edges 120.

The surface 124 of the first face 106 and/or the surface 130 of the second face 108 include the textured features 114. In one implementation, the textured features 114 are a plurality of protrusions 400 extending generally perpendicularly from the surfaces 124 and/or 130 along the length 140. In the implementation shown in FIGS. 4A-D, the protrusions 400 have a pyramidal shape, including four generally triangular faces and a rectangular base that is generally parallel to the respective surfaces 124 and/or 130. The rectangular base forms generally right angles that are coextensive with angles formed by the width 126 and the length 140 of the respective surfaces 124 and/or 130. Each face of the protrusions 400 is adjacent to two other faces of the same protrusion 400 that extend outwardly from the respective surfaces 124 and/or 130 where they adjoin to form a tip. The protrusions 400 shown in FIGS. 4A-D are relatively small pyramids having, for example, a height to the tip ranging from approximately 0.25 mm and 0.5 mm and base edges having a length between approximately 0.5 mm and 1.0 mm.

In one implementation, the protrusions 400 are arranged in rows, such that the rectangular base of each of the protrusions 400 abut the bases of adjacent protrusions 400. A plurality of the protrusions 400 extend from the first side 110 to the second side 112 to form the rows, and the rows, in turn, extend from the distal leading end 102 to the proximal trailing end 104 to form a series of rows. Further, it will be appreciated that the first and second faces 106 and 108 may include any number or configuration of the protrusions 400 and that the textured features 114 may cover all or a portion of the surface 124 of the first face 106 and/or the surface 130 of the second face 108.

In one implementation, the first and second sides 110 and 112 each include the slot 136 defined in the side surface 132 extending distally from the notch 122 formed in the proximal surface 118 at an approximate center of each of the second pair of proximal edges 120. As such, the slot 136 is generally centered in the side surface 132 between the surface 124 of the first face 106 and the surface 130 of the second face 108. In one implementation, the slot 136 is generally dimensionally constant for a majority of a length of the slot 136 extending from the notch 122 until reaching the sloped transition 138 extending from an inner surface of the slot 136 to the side surface 132.

Turning to FIGS. 5A-D, in one implementation, the distal leading portion 100 includes the distal leading end 102 generally opposite the proximal trailing end 104, the first face 106 generally opposite the second face 108, and the first side 110 generally opposite the second side 112. In one implementation, the first and second sides 110 and 112 each have a length 506 of approximately 10 mm, and the distal leading end 102 and the proximal trailing end 104 each have a length 502 of approximately 5 mm.

The first face 106 extends between the distal leading end 102 and the proximal trailing end 104. In one implementation, the first face 106 is generally parallel with the second face 108. A height of the proximal trailing end 104 may be greater than or equal to a height of the distal leading end 102. In one implementation, the first and second faces 106 and 108 include textured features 114 that provide friction between the spinal facet joint and the implant.

In one implementation, the distal leading end 102 includes the distal surface 116 and the proximal trailing end 104 includes the proximal surface 118. In one implementation, the distal and proximal surfaces 116 and 118 are planar surfaces forming a generally rectangular shape. In one implementation, the distal surface 116 has a height 504 that is approximately 2.8 mm. The distal surface 116 includes a first pair of distal edges 128 extending between the first and second sides 110 and 112 and a second pair of distal edges 134 extending between the first and second faces 106 and 108. Similarly, the proximal surface 118 includes a first pair of proximal edges 128 and a second pair of proximal edges 120 extending between the first and second faces 106 and 108. In one implementation, where the height of the proximal trailing end 104 is greater than the height of the distal leading end 102, the height of the second pair of proximal edges 120 is greater than the height of the second pair of distal edges 134, such that a surface 124 of the first face 106 and a surface 130 of the second face 108 slope upwardly from the distal leading end 102 to the proximal trailing end 104 along the length 140 extending proximally.

In one implementation, the surface 124 of the first face 106 and the surface 130 of the second face 108 are planar surfaces having a generally rectangular shape formed from the length 140 and the width 126 that is generally coextensive with the first pair of edges 128. The first and second sides 110 and 112 each include the side surface 132 extending between the distal leading end 102 and the proximal trailing end 104. In one implementation, the side surface 132 is a generally planar surface having a pair of opposed edges that are generally coextensive with the second pair of distal edges 134 and the second pair of proximal edges 120.

The surface 124 of the first face 106 and/or the surface 130 of the second face 108 include the textured features 114. In one implementation, the textured features 114 are a plurality of protrusions 500 extending generally perpendicularly from the surfaces 124 and/or 130 along the length 140. In the implementation shown in FIGS. 5A-D, the protrusions 500 have a pyramidal shape, including four generally triangular faces and a rectangular base that is generally parallel to the respective surfaces 124 and/or 130. The rectangular base forms generally right angles that are coextensive with angles formed by the width 126 and the length 140 of the respective surfaces 124 and/or 130. Each face of the protrusions 500 is adjacent to two other faces of the same protrusion 500 that extend outwardly from the respective surfaces 124 and/or 130 where they adjoin to form a tip. The protrusions 500 shown in FIGS. 5A-D are relatively large pyramids having, for example, a height to the tip ranging from approximately 0.5 mm and 1.5 mm and base edges having a length between approximately 1.0 mm and 2.0 mm.

In one implementation, the protrusions 500 are arranged in rows, such that the rectangular base of each of the protrusions 500 abut the bases of adjacent protrusions 500. A plurality of the protrusions 500 extend from the first side 110 to the second side 112 to form the rows, and the rows, in turn, extend from the distal leading end 102 to the proximal trailing end 104 to form a series of rows. In one implementation, there may be gaps between the rows that extend from the first side 110 to the second side 112 to accommodate relatively larger sized protrusions 500. Further, it will be appreciated that the first and second faces 106 and 108 may include any number or configuration of the protrusions 500 and that the textured features 114 may cover all or a portion of the surface 124 of the first face 106 and/or the surface 130 of the second face 108.

In one implementation, the first and second sides 110 and 112 each include the slot 136 defined in the side surface 132 extending distally from the notch 122 formed in the proximal surface 118 at an approximate center of each of the second pair of proximal edges 120. As such, the slot 136 is generally centered in the side surface 132 between the surface 124 of the first face 106 and the surface 130 of the second face 108. In one implementation, the slot 136 is generally dimensionally constant for a majority of a length of the slot 136 extending from the notch 122 until reaching the sloped transition 138 extending from an inner surface of the slot 136 to the side surface 132.

As can be understood from FIGS. 6A-D, in one implementation, the distal leading portion 100 includes the distal leading end 102 generally opposite the proximal trailing end 104, the first face 106 generally opposite the second face 108, and the first side 110 generally opposite the second side 112. In one implementation, the first and second sides 110 and 112 each have a length 612 of approximately 10 mm, and the distal leading end 102 and the proximal trailing end 104 each have a length 608 of approximately 5 mm.

The first face 106 extends between the distal leading end 102 and the proximal trailing end 104. In one implementation, the first face 106 is generally parallel with the second face 108. A height of the proximal trailing end 104 may be greater than or equal to a height of the distal leading end 102. In one implementation, the first and second faces 106 and 108 include textured features 114 that provide friction between the spinal facet joint and the implant.

In one implementation, the distal leading end 102 includes the distal surface 116 and the proximal trailing end 104 includes the proximal surface 118. In one implementation, the distal and proximal surfaces 116 and 118 are planar surfaces forming a generally rectangular shape. In one implementation, the distal surface 116 has a height 610 that is approximately 5.6 mm. In one implementation, where the height of the proximal trailing end 104 is greater than the height of the distal leading end 102, the surface 124 of the first face 106 and the surface 130 of the second face 108 slope upwardly from the distal leading end 102 to the proximal trailing end 104.

In one implementation, the surface 124 of the first face 106 and the surface 130 of the second face 108 are planar surfaces having a generally rectangular shape, and the first and second sides 110 and 112 each include the side surface 132 extending between the distal leading end 102 and the proximal trailing end 104.

The surface 124 of the first face 106 and/or the surface 130 of the second face 108 include the textured features 114 defined therein. In one implementation, the textured features 114 are a plurality of dimples 600 having a generally spherical imprint or indentation 602 having a radial depth generally perpendicularly into the respective surfaces 124 and/or 130. In one implementation, the dimples 600 are arranged in rows, such that the indentations 602 overlap with at least a portion of an adjacent indentation 602. A plurality of the dimples 600 extend from the first side 110 to the second side 112 to form the rows, and the rows, in turn, extend from the distal leading end 102 to the proximal trailing end 104 to form a series of rows. The effect creates a grid-like pattern of the dimples 600 forming towers 604 between the indentations 602. In one implementation, the towers 604 are generally planar surfaces. The degree of overlap of the indentations 602 and the depth of the indentations 602 can vary accordingly so as to provide an appropriate amount of friction and grip between the implant and the bone surface. For example, in one implementation, the indentations 602 may have a vertical depth of approximately 0.25 mm to 1.0 mm and a diameter of approximately 0.5 mm to 1.5 mm. Further, it will be appreciated that the first and second faces 106 and 108 may include any number or configuration of the dimples 600 and that the textured features 114 may cover all or a portion of the surface 124 of the first face 106 and/or the surface 130 of the second face 108.

In one implementation, the first and second sides 110 and 112 each include the slot 136 defined in the side surface 132 extending distally from the notch 122 formed in the proximal surface 118 at an approximate center of each of the second pair of proximal edges 120. As such, the slot 136 is generally centered in the side surface 132 between the surface 124 of the first face 106 and the surface 130 of the second face 108. In one implementation, the slot 136 is generally dimensionally constant for a majority of a length of the slot 136 extending from the notch 122 until reaching the sloped transition 138 extending from an inner surface of the slot 136 to the side surface 132.

Referring to FIGS. 7A-D, in one implementation, the distal leading portion 100 includes the distal leading end 102 generally opposite the proximal trailing end 104, the first face 106 generally opposite the second face 108, and the first side 110 generally opposite the second side 112. In one implementation, the first and second sides 110 and 112 each have a length 706 of approximately 10 mm, and the distal leading end 102 and the proximal trailing end 104 each have a length 702 of approximately 5 mm.

The first face 106 extends between the distal leading end 102 and the proximal trailing end 104. In one implementation, the first face 106 is generally parallel with the second face 108. A height of the proximal trailing end 104 may be greater than or equal to a height of the distal leading end 102. In one implementation, the first and second faces 106 and 108 include textured features 114 that provide friction between the spinal facet joint and the implant.

In one implementation, the distal leading end 102 includes the distal surface 116 and the proximal trailing end 104 includes the proximal surface 118. In one implementation, the distal and proximal surfaces 116 and 118 are planar surfaces forming a generally rectangular shape. In one implementation, the distal surface 116 has a height 704 that is approximately 3.6 mm. The distal surface 116 includes a first pair of distal edges 128 extending between the first and second sides 110 and 112 and a second pair of distal edges 134 extending between the first and second faces 106 and 108. Similarly, the proximal surface 118 includes a first pair of proximal edges 128 and a second pair of proximal edges 120 extending between the first and second faces 106 and 108. In one implementation, where the height of the proximal trailing end 104 is greater than the height of the distal leading end 102, the height of the second pair of proximal edges 120 is greater than the height of the second pair of distal edges 134, such that a surface 124 of the first face 106 and a surface 130 of the second face 108 slope upwardly from the distal leading end 102 to the proximal trailing end 104 along the length 140 extending proximally.

In one implementation, the surface 124 of the first face 106 and the surface 130 of the second face 108 are planar surfaces having a generally rectangular shape formed from the length 140 and a width that is generally coextensive with the first pair of edges 128. The first and second sides 110 and 112 each include the side surface 132 extending between the distal leading end 102 and the proximal trailing end 104. In one implementation, the side surface 132 is a generally planar surface having a pair of opposed edges that are generally coextensive with the second pair of distal edges 134 and the second pair of proximal edges 120.

The surface 124 of the first face 106 and/or the surface 130 of the second face 108 include the textured features 114. Further, the side surfaces 124, the distal surface 116, and/or the proximal surface 118 may include the textured features 114. In one implementation, the textured features 114 are a plurality of grit particles 700 extending generally perpendicularly from the surfaces 124 and/or 130 along the length 140. The grit particles 700 may be a variety of shapes adapted to fuse the implant to the bone surface. In the implementation shown in FIGS. 7A-D, the grit particles 700 have a semi-circular, bubble-like shape. The grit particles 700 shown in FIGS. 7A-D have a diameter ranging from approximately 0.1 mm and 1.0 mm.

In one implementation, the grit particles 700 are randomly adhered to the respective surfaces 124 and 130, such that the surfaces 124 and 130 may contain differences in the layout of the textured features 114. The grit particles 700 may be applied by a variety of suitable means to adhere the grit particles 700 to the material of the surfaces 124 and 130. In another implementation, the grit particles 700 are arranged relatively uniformly (i.e., in rows or strips) on the respective surfaces 124 and 130. Further, it will be appreciated that the first and second faces 106 and 108 may include any number or configuration of the grit particles 700 and that the textured features 114 may cover all or a portion of the surface 124 of the first face 106 and/or the surface 130 of the second face 108.

In one implementation, the first and second sides 110 and 112 each include the slot 136 defined in the side surface 132 extending distally from the notch 122 formed in the proximal surface 118 at an approximate center of each of the second pair of proximal edges 120. As such, the slot 136 is generally centered in the side surface 132 between the surface 124 of the first face 106 and the surface 130 of the second face 108. In one implementation, the slot 136 is generally dimensionally constant for a majority of a length of the slot 136 extending from the notch 122 until reaching the sloped transition 138 extending from an inner surface of the slot 136 to the side surface 132.

Turning to FIGS. 8A-D, in one implementation, the distal leading portion 100 includes the distal leading end 102 generally opposite the proximal trailing end 104, the first face 106 generally opposite the second face 108, and the first side 110 generally opposite the second side 112. In one implementation, the first and second sides 110 and 112 each have a length 806 of approximately 10 mm, and the distal leading end 102 and the proximal trailing end 104 each have a length 802 of approximately 5 mm.

The first face 106 extends between the distal leading end 102 and the proximal trailing end 104. In one implementation, the first face 106 is generally parallel with the second face 108. A height of the proximal trailing end 104 may be greater than or equal to a height of the distal leading end 102. In one implementation, the first and second faces 106 and 108 include textured features 114 that provide friction between the spinal facet joint and the implant.

In one implementation, the distal leading end 102 includes the distal surface 116 and the proximal trailing end 104 includes the proximal surface 118. In one implementation, the distal and proximal surfaces 116 and 118 are planar surfaces forming a generally rectangular shape. In one implementation, the distal surface 116 has a height 804 that is approximately 3.9 mm. The distal surface 116 includes a first pair of distal edges 128 extending between the first and second sides 110 and 112 and a second pair of distal edges 134 extending between the first and second faces 106 and 108. Similarly, the proximal surface 118 includes a first pair of proximal edges 128 and a second pair of proximal edges 120 extending between the first and second faces 106 and 108. In one implementation, where the height of the proximal trailing end 104 is greater than the height of the distal leading end 102, the height of the second pair of proximal edges 120 is greater than the height of the second pair of distal edges 134, such that a surface 124 of the first face 106 and a surface 130 of the second face 108 slope upwardly from the distal leading end 102 to the proximal trailing end 104 along the length 140 extending proximally.

In one implementation, the surface 124 of the first face 106 and the surface 130 of the second face 108 are planar surfaces having a generally rectangular shape formed from the length 140 and a width that is generally coextensive with the first pair of edges 128. The first and second sides 110 and 112 each include the side surface 132 extending between the distal leading end 102 and the proximal trailing end 104. In one implementation, the side surface 132 is a generally planar surface having a pair of opposed edges that are generally coextensive with the second pair of distal edges 134 and the second pair of proximal edges 120.

The surface 124 of the first face 106 and/or the surface 130 of the second face 108 include the textured features 114. Further, the side surfaces 124, the distal surface 116, and/or the proximal surface 118 may include the textured features 114. In one implementation, the textured features 114 are a plurality of pits 800 extending generally perpendicularly into the surfaces 124 and/or 130 along the length 140. The pits 800 may be a variety of shapes adapted to fuse the implant to the bone surface. For example, the pits 800 may be shaped like a negative imprint of the grit particles 700, the dimples 600, the protrusions 400, 500 or any similar feature. In the implementation shown in FIGS. 8A-D, for example, the pits 800 are negative imprints of a semi-circular, bubble-like shape. The depth of such an imprint and the imprint diameter will vary accordingly to achieve adequate friction between the implant and the bone. For example, the pits 800 shown in FIGS. 8A-D have a diameter ranging from approximately 0.1 mm and 1.0 mm.

The surfaces 124 and 130 may undergo a reductive surface treatment, including, without limitation, abrasive blasting, chemical treating, and the like, to achieve the pits 800. In addition to a reductive surface treatment, an additive treatment may be used to texture the surfaces 124 and 130 to add a pre-textured layer. In one implementation, the pits 800 cover the respective surfaces 124 and 130 in a random orientation, such that the surfaces 124 and 130 may contain differences in the layout of the textured features 114. In another implementation, the pits 800 are arranged relatively uniformly (i.e., in rows or strips) on the respective surfaces 124 and 130. Further, it will be appreciated that the first and second faces 106 and 108 may include any number or configuration of the pits 800 and that the textured features 114 may cover all or a portion of the surface 124 of the first face 106 and/or the surface 130 of the second face 108.

In one implementation, the first and second sides 110 and 112 each include the slot 136 defined in the side surface 132 extending distally from the notch 122 formed in the proximal surface 118 at an approximate center of each of the second pair of proximal edges 120. As such, the slot 136 is generally centered in the side surface 132 between the surface 124 of the first face 106 and the surface 130 of the second face 108. In one implementation, the slot 136 is generally dimensionally constant for a majority of a length of the slot 136 extending from the notch 122 until reaching the sloped transition 138 extending from an inner surface of the slot 136 to the side surface 132.

As can be understood from FIGS. 9-16, a distraction system 900 is configured to minimally invasively or percutaneously deliver implementations of the composite spinal implant including the distal leading portion 100 and optionally the proximal trailing anchor portion 200 into a patient spinal facet joint space via, for example, a posterior approach. In one implementation, the system 900 includes a delivery tool 902 and a guide tube 904, both of which extend from a respective leading distal end 906, 907 to a respective trailing proximal end 908, 909. As can be understood from FIG. 9, the delivery tool 902 can be receive in the lumen of the guide tube 904 to bring about the delivery of the implant 100 into the target spinal facet joint. The system 900 may further include a decorticator 936, an injector 948, a chisel 960, a place holding chisel 974, and a malleting tool 980.

For a detailed description of the delivery tool 902, reference is made to FIG. 10. In one implementation, the delivery tool 902 includes a tubular body 910 with a handle arrangement 912 at the trailing proximal end 908. The handle arrangement 912 may further include one or more members 914 for engaging the guide tube 904 as can be understood from FIG. 9. In one implementation, a plunger 916 extends through a lumen 918 of the tubular body 910 and includes a handle 920 at the trailing proximal end 906. The plunger 916 may be used to distally push the implant from an interference fit engagement with the arms 922 of the delivery tool distal end 906.

In one implementation, the tubular body 910 at the leading distal end 906 includes opposed prongs 922 between which the implant, including the distal leading portion 100 and the proximal trailing anchor portion 200, may be supported. The prongs 922 include longitudinally extending ridges that are adapted to be received into and engage the respective slots 136 and 220 of the distal leading portion 100 and the proximal trailing anchor portion 200. In one implementation, the plunger 916 is spring biased to keep the plunger 916 proximally displaced in the lumen 918 of the tubular body 910, such that distal force exerted against the handle 920 causes the plunger 216 to distally displace to eject the implant from the tubular body 910 at the leading distal end 906.

Turning to FIG. 11, a detailed description of the guide tube or tool 904 is provided. In one implementation, the guide tube 904 includes a receiving assembly 926 at a proximal end 909 and a pair of anchoring forks 934 at a distal end 907 with a generally tubular shaft 924 extending there between. The anchoring forks 934 may be textured distal parallel prongs for accessing a spinal facet joint and through which the delivery tool 902 can be routed to deliver the implant 100 in the facet joint.

The guide tube 904 can also include a malleting anvil 930 having a raised surface 932 positioned on the proximal face of the receiving assembly 926 adapted for contact with a distal end of a malleting head 966 on the chisel 960 or on the delivery tool 902. Malleting on the proximal end of the chisel 960 or the delivery tool 902 can cause longitudinal forces along the length of the respective tool piece. These longitudinal forces can be transferred, at least partially, through the contact between the malleting head and the malleting anvil 930. Accordingly, relative motion between the respective tool piece and the guide tube 904 can be prevented. As such, for example, at the distal end 907 of the guide tube 904, the relative position of the distal end 972 of the chisel 960 or the delivery tool 902 relative to the distal end 907 of the guide tube 904 can be maintained. Further, in one implementation, the receiving assembly 926 includes a receiving portion 928 for receiving and engaging the members 914 or 970 of the delivery tool 902 and the chisel 960, respectively, as can be understood from FIG. 9.

As can be understood from FIG. 12, in one implementation, the decorticator 936 includes a tubular shaft portion 938, an abrasive distal end 944, and a handle 940 at a proximal end. The tubular shaft 938 may have an inner radius substantially equal to an outer radius of the shaft 976 of the place holding or guide chisel 974 of FIG. 15 and may allow for sliding movement of the decorticator 936 along the length of the chisel shaft 976 and rotationally around the chisel shaft 976. In some implementations, the inner radius of the tubular shaft 938 may be slightly or substantially larger than the outer radius of the shaft 976 of the chisel 974 allowing for more freedom of movement of the decorticator 936.

The abrasive distal end 944 of the decorticator 936 may include serrated teeth 946 as shown, or may include a more flat annular surface with a gritty surface. In the implementation shown in FIG. 12, the distal end of the tubular shaft portion 938 is chamfered and the serrated teeth 946 are located on the distal most end of the chamfered end allowing for a more directed and controllable decorticating process. As such, the decorticator 936 shown is well suited for the intra facet process reflected by many of the implementations described herein. That is, the human anatomy of the cervical spine may be such that the lateral mass of the facet joints are not perpendicular to the surface of the facet joint.

Additionally, to properly place the prongs 934 of the place holding guide chisel 974 within the joint, the guide chisel 974 may be positioned substantially parallel to articular surfaces of the facet joint. As such, the place holding or guide chisel 974 may not be positioned perpendicular to the lateral masses of the facet joints and may actually be directed with a downward slope as it extends in the distal direction. Where the decorticator 936 has an non-chamfered annular end, depending on anatomy, the decorticator 936 may be able to be placed in contact with the superior lateral mass, but may be unable to reach or contact the inferior lateral mass. In the present implementation, the chamfered end of the tubular shaft portion 938 will allow the distal tip of the chamfered end to reach and decorticate the inferior lateral mass. This chamfered distal end may define an angle to the longitudinal axis. Additionally, the teeth 946 may be relatively large or they may relatively small and may extend along the full perimeter surface of the chamfered end rather being positioned solely at the tip of the chamfered end. Additionally, a beveled edge may run along the periphery of the chamfered end. That is, along the ovular shape created by the chamfered tubular shaft portion 938, the edge is beveled. As such, when the chisel 974 is inserted into the patient and/or when the decorticator 936 is advanced along the chisel 974, the beveled edge may assist in avoiding tissue snags, and the decorticator 936 may be placed in contact with the lateral mass of the facet joints in a much smoother process and may avoid damage to neighboring tissues.

The handle 940 of the decorticator 936 may include a gripping surface along its peripheral edge and may sleevably receive the tubular shaft portion 938. The handle 940 may also include radially extending bores 942 adapted to receive a gripping tool to provide for better control and a higher amount of torsional leverage when decorticating the lateral masses of the facet joint or to allow for malleting in the longitudinal direction of the decorticator 936 to cause forceful decortication of the lateral mass. The decorticator 936 may then be retracted, rotated to a new radial position, advanced, and struck again for additional decortication.

Referring to FIG. 13, in one implementation, the injector 948 includes a longitudinal delivery shaft 950 and a seating feature 952. The longitudinal delivery shaft 950 may have any cross-section and may have a cross-sectional size adapted to fit within the guide tube 904. The longitudinal shaft 950 may have an opening 956 on its distal end 954 for directing bone paste out the distal end of the shaft 950 allowing the paste to flow into and/or over the facet joint and/or outward toward the lateral mass of a facet joint. The seating feature 952 may include a member 958 positioned around the shaft 950, which may be sized and shaped to abut the receiving portion 928 of the guide tube 904. The injector 948 may be sleevably inserted into the guide tube 904 and advanced such that the distal end of the shaft 950 is positioned between the prongs 934.

As can be understood from FIG. 14, in one implementation, the chisel 960 includes a generally cylindrical cross-section forming a shaft 962, which may have a radius substantially equal to the inner radius of the tubular shaft portion 924 of the guide tube 904 allowing for slidable insertion of the chisel 960 within the guide tube 904. Alternatively, the radius of the shaft 963 may be smaller than the inner radius of the tubular shaft 924 providing for more play and adjustability of the chisel 960 and the guide tube 904 relative to one another. The chisel 960 may include a single or doubly chamfered tip 972 at a distal end or may have a coped distal end or a combination of coping and chamfering. The tip 972 may include a roughened surface on one or more sides to aid in anchoring or docking the chisel in the facet joint. Additionally, this roughened surface may allow for roughening or decorticating the inner surfaces of the facet joint. The tip 972 may have a length adapted to extend substantially across the facet joint.

The chisel 960 may further include a handle assembly 964 may include a member 970 positioned around the shaft 962, which may be sized and shaped to abut the receiving portion 928 of the guide tube 904. The chisel 1008 may also include a longitudinally extending lumen 968 and a malleting head 966.

Turning to FIG. 15, in one implementation, the placing holding or guide chisel 974 includes a shaft 976 and a distal tip 978, which may include a tip the same or similar to the chisel 960. For example, the chisel 974 can include a coped and/or chamfered tip. Additionally, the chisel 974 can include ridges. Additionally, the chisel 974 can include a radiopaque portion on the shaft 976 adapted to allow recognition of the location of the chisel 974 while avoiding occlusion of the lateral view. The radiopaque portion can include a straight, round, square, or other shaped piece of material positioned near the distal end of the chisel 974 for locating the distal end. As also shown, the proximal end of the chisel 974 can include a hole extending transversely therethrough. The hole can adapted to receive a transverse rod or shaft extending into the hole and/or through the hole. The rod or shaft and the chisel 974 can form a T-grip or L-shaped grip for use in pulling on the chisel 974 for removal.

In one implementation, the place holding chisel 974 can be used as a place holder without occluding the lateral view of a chisel and delivery tool positioned in a contralateral facet joint. That is, upon placement of the chisel 960 and the guide tool 904 in a first facet joint, the chisel 960 may be removed and replaced with the place holding chisel 974 where the prongs 934 of the guide tube 904 maintain the position of the system 900. The guide tube 904 may also be removed and reassembled with the chisel 960 once the place holding chisel 974 is properly positioned. The guide tube 904 and chisel 960 may then be inserted into the contralateral facet joint or second joint. By replacing the chisel 960 in the first joint with the place holding chisel 974, the location of the chisel 960 and guide tube 904 in the second joint may be more readily ascertainable using lateral fluoroscopy. That is, if a radiopaque chisel or delivery device was left in place in the first joint, the fluoroscopic view of the contralateral facet joint would be relatively occluded. Upon placing the guide tube 904 properly in the second facet joint, the procedure above may continue. Upon completing treatment of the second facet joint, the guide tube 904 may be sleeved over the place holding chisel 974 still positioned in and holding the place in the first facet joint and the first facet joint may then be treated with the above procedure. It is noted that initial placement of the guide tube 904 can be conducted with the place holding chisel 974 rather than the chisel 960 to avoid having to replace the chisel 960.

Referring to FIG. 16, in one implementation, the malleting tool 980 can include a longitudinally shaped shaft with a U-shaped decorticator interface 984 at one end and a chamfered tip 982 at the other end. The decorticator interface 984 can be adapted for positioning around the guide tube 904 in a position just proximal to a malleting element of the decorticator 936. The u-shape of the decorticator interface 984 may allow the malleting tool 980 to be placed in position from the side of the guide tube 904 and selectively used as required to forcibly advance the decorticator 936.

The chamfered end of the tool 982 can be held in position while the user mallets near the decorticator interface end causing the interface 984 to contact the malleting element on the decorticator 936. The decorticator 936 may then be retracted, rotated to a new radial position, advanced, and struck again for additional decortication. The malleting tool 980 may rotate with the decorticator 936 or it may remain in a position convenient for malleting. In addition to malleting, the malleting tool 980 can be used to assist in separating several tools. That is, in some cases, the handles of a given tool piece can be difficult to separate from receiving portion. The chamfered tip 982 can be used to wedge between a given handle and the receiving portion to assist in separating the devices.

Other implementations of a distraction system 900 can be configured with alternative retaining and deployment (release or eject) methods, such as screw drives, latches, snaps, cams, adhesives, magnets, or the like.

The delivery system components depicted in FIGS. 9-16 can be used to minimally invasively implant any of the implants 100 depicted in FIGS. 1A-8D in a spinal facet joint that is the target of treatment. For example, in one embodiment, a percutaneous or minimally invasive incision is made in the posterior region of the neck to lead to the target facet joint. The access chisel 974 depicted in FIG. 15 is routed through incision under fluoroscopic guidance until the tapered distal tip 978 resides in the target facet joint and the chisel shaft 976 extends out of the patient via the incision. With the access chisel 974 so positioned, the outer decorticator 936 of FIG. 12 can be grasped and distally routed over the access chisel 974 such that the chisel shaft 976 is received in the lumen that extends longitudinally through the outer decorticator 936. With the distal decorticating end 946 of the outer decorticator 936 abutting against one or more lateral masses adjacent the target facet joint, the outer decorticator 936 can be rotated about the chisel shaft 976 to decorticate the bone surfaces of the lateral masses adjacent the target facet joint. Once decortication of the lateral masses has been sufficiently achieved, the decorticator 936 can be removed from about the chisel shaft 976 and from the patient.

With the place holding or access chisel 974 so positioned, the guide tool 904 of FIG. 11 is grasped and distally routed over the chisel 974 such that the chisel shaft 976 is received in the guide tool lumen that extends longitudinally through the guide tool shaft 924. The tapered forked distal end 907 of the guide tool 904 is distally advanced through the incision and along the chisel shaft 976 until the tapered forks 934 of the guide tool 904 are positioned inside the target facet joint, the chisel tapered distal tip 978 being located between the pair of forks 934 of the guide tool distal end 907, the guide tool shaft 924 extending out of the patient via the incision.

With the guide tool 904 so positioned, the place holding or access chisel 974 can be withdrawn out of the guide tool lumen and out of the patient, leaving the guide tool tapered forked distal end 907 residing in the target facet joint and the guide tool shaft extending out of the patient. The decorticating chisel 960 of FIG. 14 can then be distally routed through the lumen of the guide tool 904 to place the tapered decorticating distal end 972 of the chisel 960 between the guide tool forks 934 located in the target facet joint space. The decorticating chisel 960 can then be displaced distal-proximal to cause the tapered decorticating distal end 972 of the chisel 960 to remove the cartilage of the target facet joint space located between the guide tool forks 934 and further decorticate any associated bone surfaces of the target facet joint space. Once the target facet joint space surfaces have been prepped with the decorticating chisel 960, the chisel 960 can be removed from the lumen of the guide tool 904 and the patient.

The implant 100 is coupled to, and supported off of, the distal end 906 of the implant delivery tool 902 of FIG. 10. As discussed above, the coupling of the implant delivery tool distal end 906 with the implant 100 may be achieved via interference fit engagement. With the implant supported off of the distal end 906 of the implant delivery tool 902 in a manner similar to that depicted in FIG. 10, the implant 100, and the delivery tool shaft 910 on which the implant 100 is supported, are distally routed through the lumen of the guide tool 904 until the implant 100 and the delivery tool distal end 906 are located in the target facet joint space between the pair of forks 934 of the guide tool distal end 907, the delivery tool 902, the guide tool 904 and the implant 100 being coupled together as depicted in FIG. 9. With the implant 100 so positioned in the target spinal facet join space, the plunger 916 may be used to deposit the implant 100 into the target spinal facet joint space by plunging the implant 100 from the delivery tool distal end 906 via corresponding manipulation of the plunger 916 via its handle 920. Once the implant 100 is decoupled from the delivery tool 902 and deposited into the facet joint space, the delivery tool 902 can be withdrawn from the guide tool 904, which is left in place with its forked distal end 907 occupying the facet joint space and the implant 100 being located between the forks 934 of the guide tool 904. Where the implant 100 is the entirety of the implant and not simply a distal portion 100 of a composite implant 300 similar to that depicted with respect to FIGS. 1A-3C, the use of the delivery tool 902 is now complete with respect to this target spinal facet joint.

However, where the delivered implant 100 is actually a proximal portion 100 of a composite spinal implant 300 similar to that depicted with respect to FIGS. 2C-3C, the delivery of the distal anchoring portion 200 of the composite spinal implant 300 may occur in one of two ways employing the method of using the delivery tool 902 as just laid out in the immediately preceding paragraph. For example, in one embodiment, the delivery of the composite implant 300 may occur in a single delivery using the above-described methodology pertaining to the use of the delivery tool 902, wherein the proximal portion 100 and the distal portion 200 are placed together to form the composite implant 300 and then inserted into the spinal facet joint space via the delivery tool 902 by the methodology just described.

Alternatively, in another embodiment, the distal portion 100 and the anchor portion 200 of the composite implant 300 are delivered in separate trips of the delivery tool 902 down through the lumen of the guide tool 904. In other words, the distal implant portion 100 is first coupled to the delivery tool 902 and tracked down into the facet joint space via the guide tool 904, and then the process is repeated by coupling the proximal anchor portion 200 to the delivery tool 902 and tracking the proximal portion 200 down the guide tool 904 into the facet joint space, abutting in the spinal facet joint space the distal face of the proximal portion 200 to the proximal face of the distal portion 100 to establish the composite implant 300. Various tools can then be introduced down the lumen of the guide tool 904 to act on the proximal end of the anchors 204 of the anchor portion 200 to cause the anchors 204 to deploy from the anchor portion 200, thereby securing the composite implant 300 from backing out of the facet joint space.

With the implant 100 and forks 934 so positioned in the facet joint space and the guide tool shaft 924 extending from the patient, bone growth promoting paste may be plunged down the lumen of the guide tool 904 via the shaft 950 of the injector 948 being distally displaced down the lumen to cause the bone paste to exit the distal end 907 of the delivery tool 904 and extend about the implant 100 occupying the spinal facet joint space. The injector 948 and guide tool 904 can then be withdrawn from the patient, the implantation of the implant 100 in the facet joint having been completed. The process can then be repeated for another facet joint if needed.

For a further discussion regarding delivery systems and methodology, see U.S. patent application Ser. No. 12/653,283, which was filed on Dec. 10, 2009 and entitled “Verbal Joint Implants and Delivery Tools.”

The description above includes example systems, methods, techniques, instruction sequences, and/or computer program products that embody techniques of the present disclosure. However, it is understood that the described disclosure may be practiced without these specific details.

It is believed that the present disclosure and many of its attendant advantages will be understood by the foregoing description, and it will be apparent that various changes may be made in the form, construction and arrangement of the components without departing from the disclosed subject matter or without sacrificing all of its material advantages. The form described is merely explanatory, and it is the intention of the following claims to encompass and include such changes.

While the present disclosure has been described with reference to various embodiments, it will be understood that these embodiments are illustrative and that the scope of the disclosure is not limited to them. Many variations, modifications, additions, and improvements are possible. More generally, embodiments in accordance with the present disclosure have been described in the context of particular implementations. Functionality may be separated or combined in blocks differently in various embodiments of the disclosure or described with different terminology. These and other variations, modifications, additions, and improvements may fall within the scope of the disclosure as defined in the claims that follow. 

What is claimed is:
 1. A distal leading portion of a composite spinal implant for implantation in a spinal facet joint, the distal leading portion comprising: a distal leading end having a distal surface generally opposite a proximal surface of a proximal trailing end; a first surface that is parallel with a second surface, the first and second surfaces extending between the distal leading end and the proximal trailing end, the first and second surfaces having one or more textured features adapted to provide friction with the spinal facet joint; and a first side surface generally opposite a second side surface, the first side surface and the second side surface each having a slot extending distally from a notch formed in the proximal surface, the slot including a sloped transition extending from an inner surface of the slot to the respective first or second side surface, wherein the textured features include: a first ridge extending along the length of the first side surface, the first ridge including: a plurality of first teeth having a leading distal face, a trailing proximal face, and a tip formed at an intersection between the leading distal face and the trailing proximal face, each tooth of the plurality of first teeth including an inner surface generally opposite an outer surface, the inner surface forming a substantially right angle with the first surface, and the outer surface being coplanar and coextensive with the first side surface; and another plurality of first teeth having a leading distal face, a trailing proximal face, and a tip formed at an intersection between the leading distal face and the trailing proximal face, each tooth of the other plurality of first teeth including an inner surface generally opposite an outer surface, the inner surface forming a substantially right angle with the second surface, and the outer surface being coplanar and coextensive with the first side surface; and a second ridge extending along the length of the second side surface, the second ridge including: a plurality of second teeth having a leading distal face, a trailing proximal face, and a tip formed at an intersection between the leading distal face and the trailing proximal face, each tooth of the plurality of second teeth including an inner surface generally opposite an outer surface, the inner surface forming a substantially right angle with the first surface, and the outer surface being coplanar and coextensive with the second side surface, and another plurality of second teeth having a leading distal face, a trailing proximal face, and a tip formed at an intersection between the leading distal face and the trailing proximal face, each tooth of the other plurality of second teeth including an inner surface generally opposite an outer surface, the inner surface forming a substantially right angle with the second surface, and the outer surface being coplanar and coextensive with the second side surface; and for each of the pluralities of teeth: each tooth has a height extending from the tooth's tip to a respective first or second surface; the plurality includes a distal tooth that is proximate to the distal leading end, and a proximal tooth that is proximate to the proximal trailing end; and the height of the distal tooth is less that the height of the proximal tooth.
 2. The distal leading portion of claim 1, wherein, for at least one tooth of the pluralities of teeth, the trailing proximal face has a slope that is greater than a slope of the leading distal face.
 3. A composite spinal implant for implantation in a spinal facet joint, the composite spinal implant comprising: a distal leading portion having a distal leading end, a first face, and a first side, the distal leading end having a distal surface generally opposite a proximal surface of a proximal trailing end, the first face having a first surface that is generally parallel with a second surface of a second face, the first and second faces extending between the distal leading end and the proximal trailing end, such that the first and second surfaces slope upwardly from the distal lead end to the proximal trailing end along a length extending proximally, the first and second surfaces having one or more textured features adapted to provide friction with the spinal facet joint, the first side having a first side surface generally opposite a second side having a second side surface; and a proximal trailing anchor portion having a body and an anchor, the body having a distal leading end generally opposite a proximal trailing end, a first face generally opposite a second face, and a first side generally opposite a second side, the anchor being supported in the body and configured to extend at least one of outwardly from the body or outwardly and distally from the body, the distal leading end of the body adapted to abut the proximal trailing end of the distal leading portion to form the composite spinal implant; wherein the first side surface and the second side surface of the distal leading portion each have a slot extending distally from a notch formed in the proximal surface until reaching a sloped transition extending from an inner surface of the slot to the side surface of the first side or the second side and the first side and the second side of the body of the proximal trailing anchor portion each have a slot extending distally from a notch formed in a surface of the proximal trailing end of the body to a notch formed in a surface of the distal leading end of the body, the slots of the proximal trailing anchor portion being generally aligned and dimensionally consistent with the slots of the distal leading portion when the distal leading end of the body abuts the proximal trailing end of the distal leading portion.
 4. The composite spinal implant of claim 3, wherein the distal leading portion includes a groove defined in the proximal surface and at least one of the surface of the first face or the second face that aligns with an opening in the body of the proximal trailing anchor portion through which the anchor extends into the groove.
 5. The distal leading portion of claim 1, wherein a length of the implant extending from the distal end to the proximal end is approximately 0.472 inches.
 6. The distal leading portion of claim 1, wherein a height of the implant extending from the first surface to the second surface is approximately 0.127 inches.
 7. A distal leading portion of a composite spinal implant for implantation in a spinal facet joint, the distal leading portion comprising: a distal leading end having a distal surface generally opposite a proximal surface of a proximal trailing end; a first surface that is parallel with a second surface, the first and second surfaces extending between the distal leading end and the proximal trailing end, the first and second surfaces having one or more textured features adapted to provide friction with the spinal facet joint; and a first side surface generally opposite a second side surface, the first side surface and the second side surface each having a slot extending distally from a notch formed in the proximal surface, the slot including a sloped transition extending from an inner surface of the slot to the respective first or second side surface, wherein the textured features include: a first ridge extending along the length of the first side surface, the first ridge including: a plurality of first teeth having a leading distal face, a trailing proximal face, and a tip formed at an intersection between the leading distal face and the trailing proximal face, each tooth of the plurality of first teeth including an inner surface generally opposite an outer surface, the inner surface forming a substantially right angle with the first surface, and the outer surface being coplanar and coextensive with the first side surface; and another plurality of first teeth having a leading distal face, a trailing proximal face, and a tip formed at an intersection between the leading distal face and the trailing proximal face, each tooth of the other plurality of first teeth including an inner surface generally opposite an outer surface, the inner surface forming a substantially right angle with the second surface, and the outer surface being coplanar and coextensive with the first side surface; and a second ridge extending along the length of the second side surface, the second ridge including: a plurality of second teeth having a leading distal face, a trailing proximal face, and a tip formed at an intersection between the leading distal face and the trailing proximal face, each tooth of the plurality of second teeth including an inner surface generally opposite an outer surface, the inner surface forming a substantially right angle with the first surface, and the outer surface being coplanar and coextensive with the second side surface, and another plurality of second teeth having a leading distal face, a trailing proximal face, and a tip formed at an intersection between the leading distal face and the trailing proximal face, each tooth of the other plurality of second teeth including an inner surface generally opposite an outer surface, the inner surface forming a substantially right angle with the second surface, and the outer surface being coplanar and coextensive with the second side surface; and each tooth of the pluralities of teeth has a height that is greater than a height of its immediately proximal adjacent tooth.
 8. The distal leading portion of claim 7, wherein, for at least one tooth of the pluralities of teeth, the trailing proximal face has a slope that is greater than a slope of the leading distal face. 